An electric heating device works based on the principle of hot air movement. There is a plurality of electric heating tubes sequentially arranged in an electric heating device. Each of the electric heating tubes has a tube body externally covered and contacting with a thermal conductive material. Two ends of each electric heating tube are fixedly connected to an inner surface of the electric heating device. Hot air produced by the electric heating tubes flows out of the electric heating device via a hot air outlet provided on the electric heating device.
It is noted the electric heating tubes are fixedly connected at two ends to the conventional electric heating device. Any mounting and dismounting of the electric heating tubes for the purpose of maintenance and replacement thereof must be done by a professional worker to avoid undesirable damage of the electric heating tubes or the whole electric heating device.